Field of the Invention
The present invention relates to wireless communication systems, and more particularly, to a method and apparatus for performing device-to-device communication in a wireless communication system.
Related Art
Recently, commercialization of the long term evolution (LTE) system, which is the next generation of wireless communication systems, has been supported earnestly. After the necessities were recognized that mass data service is to be supported in high-quality in response to users' request as well as voice service while ensuring users' mobility, the trend is that such an LTE system has been more rapidly expanded. The LTE system provides low transmission delay, high transmission rate, high system capacity and coverage improvement.
Meanwhile, in consideration of the requests of service provider that provides services to users, seek the benefit from the improvement of performances of the existing radio access or network and the way of recouping the investment costs for wireless communication systems which have been already invested so that the LTE system has been evolved in the form of maintaining or coexisting the compatibility with 2G communication system, which is the global system for mobile communications (GSM) based on the time division multiple access (TDMA), and with 3G communication system, which is the universal mobile telecommunication system (UMTS) based on the wideband code division multiple access (W-CDMA).
Particularly, with the advent of smart phones and tablet personal computers (PCs) recently, the users of actual communication devices require the services that enable you to easily obtain or share the information desired at any place and any time they want. However, it is not easy to effectively provide real-time information that is trivial but useful for users in real life situation due to the complexity of system or time delay of the wireless communication systems.
Meanwhile, a device to device (D2D) service, which is performed through a direct communication link among communication devices, without going through a network entity such as a base station, has emerged as an issue. This may be regarded that the wireless communication system is urgently needed to be developed/improved to support the environment in which users can share and obtain various information. In relation to this, the way and technique of effective data transmission and reception in wireless communication systems, which support the D2D service, are needed.